* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html,
body,
#app {
  width: 100%;
  height: 100%;
  overflow: hidden;
}
#app {
  display: flex;
  flex-direction: column;
  background-color: #f5f5f5;
}
.app-container {
  flex: 1;
  overflow-y: auto;
}

